Steam Accumulator module is equipment which accumulates energy in form of pressurized steam which can be used later when the steam demand of the process goes above the boiler capacity.

The module is used for storing a defined energy content that is available as expansion steam during pressure reduction. The application area is the covering of peak loads e.g. if the capacity of a steam generator is exceeded briefly. The greater the water content of the accumulator, the greater the re-evaporation heat is. The steam accumulator is filled 50 % with water and is heated up with steam to the boost pressure. The accumulator is discharged by opening the shut-off devices on the consumer side. Always the exact same steam quantity that was removed previously is fed into the accumulator. As a result, it is generally not necessary to feed additional feed water into the steam accumulator during operation. A float condensate trap is provided to prevent an increasing water level.

Working principle of steam accumulators

When the saturated water at high pressure is exposed to low pressure, some amount of this water will flash off into steam by using excess sensible heat in the water. The proportion of flash steam (kg of steam/ kg of water) depends on the pressure difference to which the hot water is exposed.

When steam demand from the plant is low, and the boiler is capable of generating more steam than required (i.e. at maximum continuous rating of boiler), the surplus steam available is injected into a mass of water stored under pressure in the accumulator.

After a while, the temperature of stored water will increase to saturation temperature with respect to the pressure at which the boiler is operating and when steam demand is high such that it exceeds the maximum capacity of the boiler, then this leads to drop in pressure at accumulator which in turn leads to flashing of some proportion of water into steam, thus fulfilling the high steam demand without affecting the normal operation of the boiler.

The steam accumulator consists of a horizontal cylindrical tank with a built-in steam nozzle pipe. Equipment level the module is thermally insulated and delivered with assembled equipment ready for operation. The module is fitted with a venting, drain shut-off, filling

Equipment level

The module is thermally insulated and delivered with assembled equipment ready for operation. The module is fitted with a venting, drain shut-off, filling shut-off, steam inlet and outlet valves, an over flow and overpressure protection, a direct temperature display as well as a water level indicator.